Question: I made a necklace for my mother's birthday with $6$ beads. $4$ of the beads were red and the rest were green. Complete the number sentences to find how many green beads I used. $6$ beads in all $- \,4$ red beads $= $
Answer: $6$ can be separated into two parts: ${4}$ and $?$ We can use subtraction to find the missing part: $6 - {4} = 2$ We can also think about how much more can be added to ${4}$ to get $6$ : ${4} + 2 = 6$ The answer $ 6 - {4} = 2 $ ${4} + 2 = 6$